Air pollution has always been a by-product of daily living since ancient times. Air pollution occurs when harmful substances such as particulates and biological molecules contaminate the atmosphere [Wikipedia]. Even before humans inhabited earth, fires caused by nature caused some degree of pollution. However, since humans inhabited this planet, pollution became synonymous with civilization, from the Stone Age to the industrial revolution, and continues in today's age of technology. Urban pollution affects the health and wellbeing of the majority of the world's population, even more those people living in cities. Heavy traffic, airports, industrial emissions, and burning of fossil fuel such as wood and coal are just a few causes of air pollution.
The definition of air pollution encompasses the release of waste gases such as carbon monoxide, nitrogen oxides, chlorofluorocarbons, and sulfur dioxides into the atmosphere along with particulate matter. The significance and ill effects of air pollution are related to the pollution's concentration, chemical composition, and duration. Motor vehicle emissions are one cause of this air pollution. In 2013, the World Health Organization estimated the annual death toll due to air pollution to be around seven million humans, not including pollution-related diseases such as cardiovascular and lung disease, and cancer. Infants, children and the elderly are especially vulnerable. As emissions from factories, vehicles, fires, etc. increase, so does the amount of air pollution, especially in localities with minimal winds such as valleys or areas in which hills/mountains block prevailing winds. Air pollution tends to settle at ground level where many people work, live, and play. For example, during the latter half of the 1900s, Los Angeles experienced dangerous levels of air pollution and smog.
Many efforts have been made to reduce emissions in an attempt to reduce air pollution including imposing heavy taxes on fuels and high tolls to reduce driving and encourage carpooling, programs to encourage electric vehicles, emission reduction requirements on factories, banning of fireplaces in new construction and limiting use of fireplaces in existing construction, etc. These efforts have made impacts in reducing pollution, but there are still large urban areas that have significant air pollution and smog.
What is needed is a system that will move the air pollution and smog from these urban areas and/or scrub the polluting materials from the air.